The present disclosure herein relates to semiconductor memory devices, and more particularly, to a variable resistance memory device and to a method of forming the same.
Generally, semiconductor memory devices are classified into volatile memory devices and nonvolatile memory devices. Volatile memory devices may lose their stored data when their power supplies are interrupted. Volatiles memory devices may, for example, include a dynamic random access memory (DRAM) and a static random access memory (SRAM). Nonvolatile memory devices may maintain their stored data even when their power supplies are interrupted. Nonvolatile memory devices may, for example, include a programmable read only memory (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM), a flash memory device.
Also, according to a trend of high performance and low power in the recent semiconductor memory devices, next generation semiconductor memory devices have been developed. The next generation semiconductor memory devices may, for example, include a ferroelectric random access memory (FRAM), a magnetic random access memory (MRAM) and a phase change random access memory (PRAM). Material constituting the next generation semiconductor memory devices may have a different resistance depending on a current forced thereto or a voltage applied thereto, and have a characteristic maintaining a resistance even when a current supply or a voltage supply is interrupted.